(1) Field of the Invention
The present invention relates to an image processing apparatus for processing a document created by application software, an image processing method and a storage medium storing a program for causing image processing to be executed.
(2) Description of the Related Art
In recent years, people make an electronic document created by using a computer. Many kinds of applications are well known to make the electronic document. However, many of the documents created by such applications can be generally browsed and corrected only by the application used for the creation.
Therefore, rasterizing the document into a bitmap image makes it possible to be referred by a user who does not have the application used for creating the document. In this case, since the amount of data of the bitmap image is generally large, it is well known to reduce the amount of data by run-length compression for example.
Patent document 1 (JP-A-2003-244447) discloses a technique to improve compression efficiency of a picture portion. The technique teaches a method in which a character and a picture are separated and extracted from image data. Then a pixel value of the image data in which the character is removed from the picture portion is determined by a predetermined method.
Although this method improves the compression efficiency, it is not satisfied with quality of the compression to reuse the image data.